Table 2.

Concentrations of conjugated estrogens in postmenopausal serum determined by LC-MS.

Technique	G/S	Intact	Intact	G/S	G/S	G/S	G/S	Overall Mean pg/mL
Derivative	Dansyl	None	None	Dansyl	Dansyl	Dansyl	NMPS
Reference	35	26	12	38	39	40	Present study
pg/mL	Mean	Mean	Median	Median	Median	Median	Mean
E2-T	51.5	x	x	9.8	6.2	10.5	20.7	19.7
E2-3G	x	8.4	2.5	x	x	x	x	5.5
16α-OH-E2-T	27.9	x	x	126.0	78.4	70.5	32.5	67.1
4-MeO-E2-T	BLQ	x	x	0.8	0.6	0.8	8.2	2.6
2-MeO-E2-T	BLQ	x	x	2.3	4.7	4.0	2.5	3.4
2-MeO-E2-3G	x	6.9	2.5	x	x	x	x	4.7
4-OH-E2-T	x	x	x	x	x	x	BLQ	BLQ
2-OH-E2-T	11.1	x	x	10.4	6.6	3.5	BLQ	7.9

X = not determined

BLQ = below LLOQ

T = conjugated + unconjugated

G = glucuronide

G/S = β-glucuronidase/arylsulfatase hydrolysis as described in section 2.5.